--- a/tc/Makefile
+++ b/tc/Makefile
@@ -119,6 +119,9 @@ CFLAGS += -DCONFIG_GACT -DCONFIG_GACT_PR
 ifneq ($(IPT_LIB_DIR),)
 	CFLAGS += -DIPT_LIB_DIR=\"$(IPT_LIB_DIR)\"
 endif
+ifneq ($(XT_LIB_DIR),)
+	CFLAGS += -DXT_LIB_DIR=\"$(XT_LIB_DIR)\"
+endif
 
 LEX := flex
 CFLAGS += -DYY_NO_INPUT
